Fri 10 Apr — Your delivery promise is only as good as your postcode exclusions

Primary Audience: West Midlands DTC founder

Summary: Royal Mail updating postcode exclusions is a reminder: you can’t promise ‘next-day UK-wide’ unless you’ve checked what your carrier actually excludes, and built those rules into your checkout and comms.

Suggested Posting Day: Friday

If you’re promising “next-day UK delivery” without checking postcode exclusions, you’re setting yourself up to look unreliable.

Because your delivery promise isn’t what you wrote on your website.

It’s what your carrier will actually do for that postcode.

Royal Mail are updating their delivery speed exclusions from 13 April 2026 for Royal Mail 24/48 and Tracked 24/48.

That means more postcodes where ‘24’ doesn’t really mean 24.

This is where founders get caught out.

They buy the label (Tracked 24).

Then they build the marketing around it.

And only discover the exclusions when the angry emails land.

Mini-example.

A West Midlands brand runs a promo, advertises next-day, and ships a batch to the Highlands and Islands (and a few other awkward postcodes).

The parcels move fine.

But they’re not next-day.

So you pay twice: once for the service, and again in customer service time, refunds, and lost trust.

Practical takeaway:

Spend 20 minutes this week doing three boring checks:

1) Download your carrier’s exclusions list and highlight the postcodes your customers actually order from.

2) Update your checkout delivery estimates for those areas (even if it’s just “2–4 working days”).

3) Put a one-line note in the dispatch email so people aren’t guessing.

Where do delivery promises go wrong most in your business: cut-off times, postcode exclusions, or stock not being where you think it is?